24,089 research outputs found
Implementing Public Health Regulations in Developing Countries: Lessons from the OECD Countries
The enforcement of public health standards is a common problem in many developing countries. Public health agencies lack sufficient resources and, too often, enforcement mechanisms rely on slow and erratic judicial systems. These limitations can make traditional public health regulations difficult to implement. In this article, we examine innovative approaches to the implementation of public health regulations that have emerged in recent years within OECD countries. These approaches aim to improve compliance with health standards, while reducing dependence on both the legal system and the administrative resources of public health agencies.
This article begins by discussing some traditional forms of public health regulations; these regulations include administrative searches and inspections as well as licensing measures. Within these traditional forms of public health regulation, there are several ways of improving compliance without substantially increasing administrative costs. These measures include public disclosure and several types of sanctions, which may escalate in severity as an actor continues to flout the public health regulation.
In addition to such traditional measures, we discuss more creative approaches to reducing dependence on the judiciary and reducing administrative costs. Dependence on the judiciary can be reduced through increased reliance on alternative dispute resolution methods, such as mediation and arbitrations, as well as through the use of a public health Ombudsman. Administrative costs could also potentially be reduced through the creative use of public-private cooperation measures, such as negotiated rulemaking and self-regulating codes of conduct. Developing countries may find some useful lessons in the innovative approaches described; however, these approaches will likely need to be adapted to fit each country’s particular institutional setting
Are Computers Good for Children? The Effects of Home Computers on Educational Outcomes
Although computers are universal in the classroom, nearly twenty million children in the United States do not have computers in their homes. Surprisingly, only a few previous studies explore the role of home computers in the educational process. Home computers might be very useful for completing school assignments, but they might also represent a distraction for teenagers. We use several identification strategies and panel data from the two main U.S. datasets that include recent information on computer ownership among children -- the 2000-2003 CPS Computer and Internet Use Supplements (CIUS) matched to the CPS Basic Monthly Files and the National Longitudinal Survey of Youth 1997 -- to explore the causal relationship between computer ownership and high school graduation and other educational outcomes. Teenagers who have access to home computers are 6 to 8 percentage points more likely to graduate from high school than teenagers who do not have home computers after controlling for individual, parental, and family characteristics. We generally find evidence of positive relationships between home computers and educational outcomes using several identification strategies, including controlling for typically unobservable home environment and extracurricular activities in the NLSY97, fixed effects models, instrumental variables, and including future computer ownership and falsification tests. Home computers may increase high school graduation by reducing non-productive activities, such as truancy and crime, among children in addition to making it easier to complete school assignments.technology, computers, education
A Langevin analysis of fundamental noise limits in Coherent Anti-Stokes Raman Spectroscopy
We use a Langevin approach to analyze the quantum noise in Coherent
Anti-Stokes Raman Spectroscopy (CARS) in several experimental scenarios: with
continuous wave input fields acting simultaneously and with fast sequential
pulsed lasers where one field scatters off the coherence generated by other
fields; and for interactions within a cavity and in free space. In all the
cases, the signal as well as the quantum noise due to spontaneous decay and
decoherence in the medium are shown to be described by the same general
expression. Our theory in particular shows that for short interaction times,
the medium noise is not important and the efficiency is limited only by the
intrinsic quantum nature of the photon. We obtain fully analytic results
\emph{without} making an adiabatic approximation, the fluctuations of the
medium and the fields are self solved consistently.Comment: 12 pages, 1 figur
Universal quantum computation on a semiconductor quantum wire network
Universal quantum computation (UQC) using Majorana fermions on a 2D
topological superconducting (TS) medium remains an outstanding open problem.
This is because the quantum gate set that can be generated by braiding of the
Majorana fermions does not include \emph{any} two-qubit gate and also the
single-qubit phase gate. In principle, it is possible to create these
crucial extra gates using quantum interference of Majorana fermion currents.
However, it is not clear if the motion of the various order parameter defects
(vortices, domain walls, \emph{etc.}), to which the Majorana fermions are bound
in a TS medium, can be quantum coherent. We show that these obstacles can be
overcome using a semiconductor quantum wire network in the vicinity of an
-wave superconductor, by constructing topologically protected two-qubit
gates and any arbitrary single-qubit phase gate in a topologically unprotected
manner, which can be error corrected using magic state distillation. Thus our
strategy, using a judicious combination of topologically protected and
unprotected gate operations, realizes UQC on a quantum wire network with a
remarkably high error threshold of as compared to to
in ordinary unprotected quantum computation.Comment: 7 pages, 2 figure
Accurate statistics of a flexible polymer chain in shear flow
We present exact and analytically accurate results for the problem of a
flexible polymer chain in shear flow. Under such a flow the polymer tumbles,
and the probability distribution of the tumbling times of the polymer
decays exponentially as (where is the
longest relaxation time). We show that for a Rouse chain, this nontrivial
constant can be calculated in the limit of large Weissenberg number
(high shear rate) and is in excellent agreement with our simulation result of
. We also derive exactly the distribution functions for
the length and the orientational angles of the end-to-end vector of the
polymer.Comment: 4 pages, 2 figures. Minor changes. Texts differ slightly from the PRL
published versio
O micoparasitismo do agente causal do mofo-preto do cajueiro pelo fungo Acremonium sp.
Considerada a segunda mais importante doenca foliar do cajueiro no Brasil, sendo superada apenas pela antracnose, o mofo-preto do cajueiro foi inicialmente encontrado afetando plantas de cajueiro comum, no Estado do Maranhao ...bitstream/CNPAT-2010/5404/1/Pa-048.pd
As doenças do dendê (Elaeis guineensis Jacq.) na região amazônica brasileira.
bitstream/item/30785/1/UEPAE-BELEM-CirTec2.pd
Modification of the Charge ordering in PrSrMnO Nanoparticles
Transport and magnetic properties have been studied in two sets of sol-gel
prepared PrSrMnO nanoparticles having average particle
size of 30 nm and 45 nm. Our measurements suggest that the formation of charge
ordered state is largely affected due to lowering of particle size, but the
ferromagnetic transition temperature () remains unaffected.Comment: Accepted in J. Appl. Phy
- …